I'm willing to hear any ideas you can think of, nothing is set in stone just yet. Here is just what I was thinking of for your first idea, and I really like how it's already coming along.
BASIC POINTS:
-You are at war with an enemy faction, and you are a strong general
-Your enemy faction sends out a kidnapping party and they attack you at night and bring you back to their stronghold
-They kill you, and give you a new body, they now have your soul
-Your soul was weaker than your body during the ritual, so your new body is weak when it is first formed
-The enemy faction now has you working under their control, but you are too weak to help them in the war, so they send you to get stronger (see; small quests and basic monsters)
-As soon as you are strong enough, they send you with an attack party to fight your own faction, and you kill former allies because you have no choice. Your entire ally faction is wiped out. (see; BAWWWW)
-You realize, in this battle, that you cannot be killed, and you confront your masters with a feeling of invincibility
-You were a dumbass, they banish you to hell, and your soul is now in possession of Satan.
-You get stronger and stronger in hell, and you are immortal, so you start a quest to escape
-After fighting through hell and confronting lucifer, you beat him in some sort of riddle or some shit because he is too strong for you to try to fight any other way, you escape, but now your soul is back in your body, and you can be killed again.
-Basically, there was a scene telling you how much long you have been in hell (500 or so years)
-As you get back to earth, you realize that what was once a small enemy faction has become a large empire, and you still hold a huge grudge (see; confronting a large empire cliche)
-You infiltrate the empire, and although you are not immortal, you are still very powerful from your long life of fighting
-You start assassinating people, eventually you are found out and you are forced to flee from the empire
-You find a group much like your old faction, and join them to work against the empire
-You fall in love with some character in your faction
-Empire finds you, kills off person you are in love with
-You go back to hell and trade your soul for immortality for 10 years or however long would be a good plot device, and you make a deal with Satan to bring your lover back to life, in return you will kill off an entire empire
-You basically go on a pissed off rampage across the empire as an immortal, leaving it in shambles and starting a new kingdom
-You have X number of years left, and your kingdom is the strongest and you have flourished, and you have a family with said lover
-You die of natural causes, and this is before 10 years is up. It falls under God's jurisdiction, and he is merciful because you have destroyed an evil manipulative empire, you were a victim in the past, and you always did what was "right"
-Happy ending and shit, sequel is your son, and you're a voice in his head from heaven, (see; FUCKING NAVI)
The only large part I see missing is a party, but I dont know where I would include that. Ideas and comments appreciated.